Safety and effectiveness of an iris hook assisted phacoemulsification in vitrectomized eyes

To introduce a simple iris hook assisted phacoemulsification (PE) procedure and evaluate the safety and efficacy of it in completely vitrectomized eyes.

A single centre study which included 65 previously completely vitrectomized eyes of 62 patients who underwent cataract surgery. Patients were randomly divided into 3 groups. Patients received PE, and intraocular lens (IOL) implantation with the assistance of iris hook (Synergeties™) as group A (25 eyes); patients who received PE assisted with a 25G pars plana irrigation as group B (20 eyes), and patients who received PE performed without the help of any instrument as group C (20 eyes). Main outcome measures were surgery duration, Ultrasound (U/S) total time, endothelial cell density (ECD), cumulative dissipated energy (CDE) and complications of the procedures.

With the help of iris hook, the patients in group A had the lowest ECD loss rate (0.07±0.03, 0.09±0.03, and 0.10±0.03, P<0.05), shortest CDE (12.2±4.1, 15.8±6.0, and 16.0±6.0, P<0.05) and U/S total time (36.6±13.0s, 46.3±16.4s, and 47.6±16.1s, P<0.05), and minimal incidence of complications. The longest surgery duration was in group B (19.4±1.6min) and maximum complications rate in group C (20% miosis, 10% posterior capsular tears, 5% zonular dialysis, 5% cystoid macular edema). While best-corrected visual acuity (BCVA), intraocular pressure (IOP) and ECD did not show a significant difference among the three groups.

Without prolonged surgery duration, the iris hook assistant method can minimize heat generation during surgery and incidence of complications, which transfer the challenged PE in vitrectomized eyes into a regular surgery. It does not need any change in the hydrodynamic parameters and in the bag PE technique, easy to operate even for junior surgeons.